protein synthesis Flashcards
(15 cards)
What is the purpose of transcription?
The purpose of transcription is to create an mRNA version of the relevant segment of DNA so that it can be transported from the nucleus to the cytoplasm for translation into a polypeptide.
Where does transcription take place?
In the nucleus
What is the role of RNA polymerase in transcription?
RNA polymerase binds to the promoter region of DNA, synthesizes mRNA by adding RNA nucleotides complementary to the antisense (template) strand of DNA.
What are the sense and antisense strands of DNA?
The sense strand is the coding strand, and the antisense strand serves as the template for mRNA synthesis.
How is mRNA synthesized during transcription?
mRNA is synthesized by RNA polymerase in the 5’ to 3’ direction, with mRNA nucleotides being added based on complementary base pairing to the antisense strand of DNA.
What enzyme causes the DNA to unravel?
DNA helicase
How does the mRNA move out of the nucleus and where does it go next?
Through nuclear pores, then attaches to ribosomes
What is the role of translation?
Amino acids joining together to form a polypeptide chain
Where are these ribosomes located?
RER
How does a tRNA molecule bind to mRNA?
Via its anticodon, carrying a specific amino acid on the amino acid binding site
What bond forms between the anticodon of the tRNA and the codon of the mRNA?
Hydrogen
What happens when the second tRNA binds to the next codon of the mRNA?
The two amino acids will form a peptide bond
What causes the first tRNA molecule to leave the ribosome?
A third tRNA molecule joining the mRNA
What is formed when this process is repeated?
polypeptide chain
How is the production of this polypeptide chain ended?
Once a stop codon is reached on the mRNA
